1. First, it loads Segoe UI, if installed. Segoe UI is the font for the Windows 8 Metro.2. If Segoe UI not found, it loads Open Sans. This font is very similar to Segoe UI.3. If Open Sans not found, it loads Open Sans Web, the built-in webfont.Because Stylish doesn't support @font-face at all, the only way is to embed base-64 encoded font in the code.